Wet mateable connector

ABSTRACT

An electrical connector, for use in underwater applications. The connector comprises a male component having a least one contact pin and a female component having a contact module. The male and female components engage, in use, to form a watertight electrical connection between the at least one contact pin and the contact module. The female component further comprises a biassing module, which comprises a first biassing means and a second biassing means. The first biassing means is located radially within the second biassing means with respect to the longitudinal axis of the female component. The first biassing means such that the biassing strength of the biassing module can be tailored to control the insertion rate of the male connector during coupling of the male component to the female component accommodating large variations in axial engagement length.

The present invention relates to the field of electrical connectors foruse with sub-sea wellhead equipment but could equally be applied tosub-sea power and control applications. Equipment associated withsub-sea wellheads experience high pressures and temperatures duringcontinuous operation. Electrical connectors of this type form pressurebarriers across the wellhead components and are subject to these samesevere operation parameters.

Conventional sub-sea wellheads comprise a number of large operationalsteel assemblies which form a pressure enclosure yet allow the wellheadto be deployed in sections and work-over operations to be carried out inservice. The wellhead sections form sub assemblies which provide theinterface points for the electrical and hydraulic feed through systems.Due to the operational requirements of these wellheads, there exists, aneed for the electrical and hydraulic connectors to accommodate largevariations in the relative positions of the wellhead parts, which formthese connector interfaces. As wellheads are deployed in more aggressivedeeper locations, the need for more reservoir data increases, thereforethere is a drive towards more space saving couplers and devices.

Subsea wet mateable connectors are known in wellhead applications wherethe electrical connection is made up in an oil filled pressure balancedenvironment, and where a shuttle pin or sprung stopper provides a meansof sealing the opening for the male contact. However, due to the natureof these connectors, a problem exists whereby the connection contactsvary in position to accommodate the relative positions in the wellheadand can result in loss of continuity and lower performance due to theprecise requirements of the connection point in such connectors.

Connectors are known whereby the front contact part is sprung loaded andthe cables are formed as a coiled spring to allow large variations inengagement length. This arrangement is not ideal as it can result in theconnectors standing off from each other and the contacts not engagingproperly. The cable coil arrangement also takes up space allowing fewerservices to be provided through the wellhead.

The need to have an increased amount of instrumentation on sub-seaequipment, particularly with requirements for “intelligent wells”, haslead to a need for more compact and space saving electrical couplers,whilst retaining the ability to accommodate large tolerances inconnection height within the small diametral space envelope that isusually required in the sub-sea wellhead environment. Current connectorsfail to provide this.

Additionally, it is known that in some circumstances the male connectorcan be exposed for up to 1 year in a sub-sea well without protection andthat current connectors require solder terminations to be performed onthe drill floor. The proposed invention provides a means by which themale contacts are continuously protected and the cable termination issimplified.

Accordingly a connector is required that is simpler to assemble and usethan those in current use, whilst providing adequate protection of itsinternal components from the harsh sub-sea and wellhead environment,—yetaccommodating a significant level of tolerance in the longitudinal andaxial directions.

According to the present invention there is provided an electricalconnector, for use in underwater applications, the connector comprisinga male component having at least one contact pin and a female componenthaving a contact module. The male and female components engaging, inuse, to form a watertight electrical connection between the at least onecontact pin and the contact module, the female component furthercomprising a biassing module, the biassing module comprising a firstbiassing means and a second biassing means, the first biassing meanshaving a different resilience to that of the second biassing means suchthat the biassing strength of the biassing module can be tailored tocontrol the insertion rate of the male connector during coupling of themale component to the female component.

One or more of the biassing means may be springs and the contact moduleand the biassing module may be located within an oil-filled chamber. Thefirst biassing means may be located radially within the second biassingmeans with respect to the longitudinal axis of the female component. Thecontact module may be a slideable unit which, in use, is seated on thetip of the contact pin. The male component may further comprise a wiperassembly. The wiper assembly, in use, provides a seal between thecontact pin and the contact module, whilst assisting with the axialalignment of the components during engagement. The wiper assembly may befilled with electrically insulating grease and may telescope in length.

At least one of the contact pins or contact module sliding contactelements may, in use, be connected to a cable by a crimping assembly,where the crimping assembly may latch and lock upon insertion of a cablesealing boot. The element is crimped by movement of a sealing boot whichis associated therewith.

The electrical connector may form a single or dual electrical contactbetween the contact pin and the contact module. When the electricalcontact is a dual contact the contact pin may be formed from twoconducting sections which are insulated from one another, the firstsection lying inside the second section.

The contact module may float radially within the housing unit of thefemale component and can be centralised by a biassing means tocompensate for radial misalignment. Furthermore, three retaining membersmay be located in the housing unit to permanently engage the contacthousing such that torsional strain may be prevented within the femalecomponent.

Examples of the present invention will now be described with referenceto the accompanying drawings, in which:

FIG. 1 shows a cross sectional view of three stages of engagement of asingle contact, sub-sea, electrical connector of the present invention;

FIG. 2 illustrates the cable termination module from FIG. 1 a in greaterdetail;

FIG. 3 illustrates the sliding contact module from FIG. 1 c in greaterdetail;

FIG. 4 illustrates the contact between the engaged male and femalecomponents from FIG. 1 c in greater detail;

FIG. 5 shows a cross sectional view of the female component of the dualcontact sub-sea electrical connector of the present invention;

FIG. 6 shows a normal cross section of the view shown in FIG. 5,illustrating the second biassing means of the female component;

FIG. 7 shows a close up view of the contact and spring modules shown inFIG. 6;

FIG. 8 shows a cross sectional view of the male component of the dualcontact sub-sea electrical connector of the present invention;

FIG. 9 shows the contact pin from FIG. 8 in greater detail;

FIG. 10 shows a cross sectional view of three stages of the engagementoperation of the dual contact, sub-sea, electrical connector; and

FIG. 11 shows a cross sectional view of a fully engaged dual contactsub-sea electrical connector.

An electrical connector 1 according to the present invention isillustrated in FIG. 1. A male component 2 of the connector 1 comprises acontact pin 4, a wiper assembly 5, a wiper spring seal mechanism 6, acable termination module 7, and an outer housing unit or alignmentsleeve 8. A female component 3 comprises a sliding contact module 9within a housing unit 13. The contact module 9 comprises at least onesliding contact pin 10, a shuttle pin 15, a biassing module 11, a cabletermination module 7 and a wiper diaphragm seal 14.

FIG. 1 a to 1 c shows the connector mating sequence. As the connectorsare brought together alignment sleeve 8 centralises and aligns the plugnose housing 13 ejecting sand/silt and water through ports 47.

Since the wiper seal spring 6 is pre-set to a higher load than contactmodule return spring 11 b, wiper seal assembly 5 enters housing 13 toform a seal between male and female components 2, 3. The contact module9 and shuttle pin assembly 15 are driven back along the sliding contactpin 10.

Further engagement allows the shuttle pin 15 to be driven back withoutmoving contact module assembly 9 due to the different spring settings.As the shuttle pin 15 strikes an end stop tube 43 the contact module 9is then able to travel further along the sliding contact pin 10, thusallowing longitudinal tolerances to be accommodated.

FIG. 1 c shows the components in their fully engaged state where themale pin 4 is fully deployed into contact module 9.

Both male and female connectors are terminated to cable 20 by means of aself locking and latching crimp termination element 7. The cabletermination is by means of a self locking and latching crimp terminationmethod, which will now be described. FIG. 2 shows the elements of thetermination module 7 which comprises; a terminal socket contact 39, aboot seal 40, an anti extrusion cap 33, a locking tube 34, a latchingtube 35, and a crimping contact 36. The latching tube 35 is slotted andis attached to the terminal contact housing. In use, the cable 20 is fedthrough the boot assembly 40 which is an elastomer moulding. The cableend is then prepared to allow a crimp contact 36 to be fitted to it. Thecrimp contact 36 is then pushed into the terminal latching tube 35,which grips around the crimp contact profile. The boot seal 40 is thenslid along the cable to lock and seal the terminal in place. In thecurrent example, the locking tube 34 is made from a rigid electricalinsulation material which envelops the terminal copper elementsproviding good electrical insulation characteristics at elevatedtemperatures. This feature eliminates the need to perform skilledsoldering at an installation site during the cable attachment process.

FIGS. 3 and 4 illustrate the sliding contact module in greater detail.The sliding contact module 9 comprises a central metallic contact tubeelement 17 formed inside an electrical insulator 41. Wiper diaphragmseal 14 is oil 42 filled and provides a pressure compensation means toallow free movement of the sliding contact module 9 and central shuttlepin 15. A reverse tube element 43 provides a sliding contact arrangementwith contact pin 10 the opening for which is sealed by wiper seal 44.The reverse tube element 43 also acts as a dead stop for shuttle pin 15and supports spring 11 a. Dielectric oil passages 45 are provided in thereverse tube element 43 to allow oil 42 to be displaced as the slidingcontact module 9 reciprocates during connection on vented bearing rings46.

When the components 2, 3 are disconnected, the sliding contact module 9is driven towards the tip of the female component 3 by a biasing spring11 b which has a higher spring pre-load and stiffness than the centralshuttle spring biasing spring 11 a. However, the biasing spring forcecloses the opening into housing 13 preventing oil 42 leakage.

The male connector 2 has a centrally mounted contact pin 4 which isinsulated along its length. The front portion of the pin is conicallyformed to provide a centralising feature 48. The pin has a contact bandregion 25 which engages the socket contact of the mating femaleconnector 3 to form electrical connection 16. A grease filled wiperassembly 5 forms a sealing envelope around the male contact band 25 whendisconnected, protecting the male contact band 25 by sealing ontoinsulation portions, located either side of the contact band 25 region.The male wiper assembly 5 is driven forward when the components 2, 3 aredisconnected by the wiper seal spring 6, which has a higher pre-loadthan the sliding contact module spring 11 b.

Dielectric oil 42 around the contact module 9 passes from the rear tothe front section through vent grooves in the electrical insulator 41.Compensation bladder 49 allows the pin displacement volume to beaccommodated as well as thermal temperature variations. Port 50 allowspressure equalisation to the outside environment.

FIG. 5 illustrates a cross section of the female component 3 of a dualcontact sub-sea electrical connector 1. Components corresponding tothose in the example of FIG. 1 are numbered identically. In this examplethe contact module 9 floats within the female housing unit 12. Thecontact module 9 is centralised prior to engagement by three radialsprings 18 which allow a small amount (typically±5 mm) of lateralmovement. This lateral flexibility further assists in locating themating components 2, 3. In order to prevent torsional strain from beingintroduced in the female component 3, three screws 19 are located in thehousing unit 12 to permanently engage the contact module housing 13.

In this example two single wire electrical cables 29 a are run throughsteel conduit tubes 29 b to form a flexible, pressure tight, sealingenclosure which protects the cables 29 a from the environment yet allowsfree movement of the contact module housing 13.

The cable termination modules 7, one for each wire 29, and thecorresponding sliding contact pins 10 are positioned symmetricallyeither side of the centre line of the female component 3. A springsupport pin 17 is located on the centre line to restrict the compressionof the first biassing means 11 a by the shuttle pin 15, such that thecorrect positioning of the contact pin 4 is achieved, in use, andsuitable electrical connections 16 (FIGS. 10 & 11) can be made. Theshuttle pin arrangement translates concentric contacts into slidingcontacts which accommodate the longitudinal tolerance.

In the dual contact arrangement of this example the second biassingmeans 11 b is provided through a second arrangement 30 (FIG. 6), wheretwo springs 11 b are placed about the centre line of the femalecomponent 3 and housed in spring module 51 in an alternative plane tothe sliding contact pins 10 (FIG. 5). This second biassing means 11 b ofthe spring module 51, which is mechanically linked to contact module 9through clip 38 (FIG. 7), is set with a higher pre-load than the firstbiassing means 11 a to allow shuttle pin 15 to first compress spring 11a until it strikes support pin 17 setting the relative contact positions52 associated with the contact bands 25, 26 on the contact pin 4 of themale component 2. Further longitudinal motion of the contact module 9allows the wellhead axial tolerances to be achieved whilst maintainingelectrical continuity and insulation performance.

Free movement of the internal components of the contact module 9 (FIG.7) is achieved by allowing the free passage of oil 42 around the springmodule 51 and contact module 9 by vent passages 53. Fluid displacementdue to the sliding contacts 10 is accommodated by inclusion ofdiaphragms 31 which also form electrical insulation elements withsliding contact pins 10. The diaphragms 31 independently equalisepressure across each of the contacts through drillings 37 which feedcontact cavities created by front wiper seal 14, rear wiper seal 44 andintermediate seal 54. Thus both contacts are effectively independent andelectrically isolated from each other and earth at all times.

The male component 2 of the dual contact example of the presentinvention is illustrated in FIGS. 8 and 9. Prior to engagement with thefemale part 3, the contact bands 25, 26 of the contact pin 4 areenveloped and sealed by a telescopic wiper assembly 5. This wiperassembly 5 is retained in place by an abutment in housing 8 and wiperspring mechanism 6 which surrounds the remainder of the contact pin 4and the cable termination module 7. The wiper assembly 5 is filled withelectrically insulating grease or similar substance 32 and, in use,wipes and lubricates the contact pin 4 to remove any trace of waterand/or silt from the surface of the contact pin 4, thus ensuring abetter electrical connection 16. Four vent ports 27 with ejection slotsare located within face 22 of the male component 2 for water and sandejection during coupling.

The contact pin 4 is shown in greater detail in FIG. 9. The wiper 5profile provides a mechanical, axial alignment feature during couplingforming a location and sealing arrangement with housing 13. Two separateinsulated contacts 16 are provided in pin 4 by arranging a centralconductor rod 23 concentrically within an outer conductor tube 24. Thecontact of the inner rod 23 being located in a band 25 at the tip of thepin 4 and the second contact band 26 being located further down thelength of the pin 4 and insulated from the first band 25. Each band 25,26 feeds back to a single wire 29 at the cable termination module 7 viathe copper alloy conductor rods 23, 24.

FIGS. 10 a to 10 c illustrate engagement of the male 2 and female 3components of the dual contact electrical connector 1, which is similarto the single contact connector of FIG. 1.

The concentric design of the connector 1 allows it to be used at anyrotational orientation, thus simplifying the coupling and mountingoperations. In use, the male 2 and female 3 components are broughttogether and the wiper diaphragm seal 14 of the female component 3engages the contact pin 4 of the male component 2 excluding water at thecontact face by virtue of the elastomer seals and spring forces. Thiswater, along with any sand and silt borne in it, is flushed throughports 27 and 47. As the coupling process is further advanced a secondaryport 55 provides a pathway to the primary ports 27, 47 for further waterto be ejected. As the longitudinal motion continues the tip of thehousing 13 moves from resting on the wiper diaphragm seal 14 to belocated on and form a seal with the wiper assembly 5 of the malecomponent 2, whilst maintaining the seal between the housing 13 and itsadjacent component 14, 5 (FIG. 10 a to 10 b). In this way a continuouscontact protection envelope is established prior to engagement of thecontacts 16. The tip 48 of the contact pin 4 passes through the wiperdiaphragm seal 14 and mates with the contact module 9 at the tip of theshuttle pin 15. Once the transfer of housing 13 is complete, furthermotion causes the housing 13 to force the wiper assembly 5 along thecontact pin 4 and the wiper spring mechanism 6 is compressed (FIG. 10 bto 10 c). The corresponding motion of the shuttle pin 15 caused by thecontact pin 4 compresses the first biassing means 11 a until the motionis restricted by the spring support pin 17 (FIG. 10 c). At this level ofpenetration, the relative positions of the contact module 9 and thecontact pin 4 are such that an electrical connection 16 is establishedbetween the two. At this point, minimum engagement can be said to havebeen achieved.

Due to the sliding contact pin 10, the second biassing means 11 b of thefemale component 3 (see FIG. 6) and the distance between the collar 21of the female component 3 and the face 22 of the male component 2, thereremains a degree of travel in the longitudinal sense. This marginaccommodates the large tolerances that may be required in conditionsassociated with sub-sea well head connections/equipment (not shown).Maximum engagement is illustrated in FIG. 11 where collar 21 is indirect contact with face 22 of the male component 2. This level ofengagement provides the additional feature of enhancing the dissipationof the engagement loads through the housing components 8, 12 protectingthe male contact pin from severe end loads.

1. An electrical connector, for use in underwater applications, theconnector comprising a male component having at least one contact pinand a wiper assembly that telescopes in length, and a female componenthaving a contact module, the male and female components engaging, inuse, to form a watertight electrical connection between the at least onecontact pin and the contact module, the female component furthercomprising a biassing module, the biassing module comprising a firstbiassing means and a second biassing means, the first biassing meanshaving a different resilience to that of the second biassing means suchthat the biassing strength of the biassing module can be tailored tocontrol the insertion rate of the male component during engagement ofthe male component and the female component; and wherein two electricalcontacts are formed between the at least one contact pin and the contactmodule: and the at least one contact pin is formed from two conductingsections insulated from one another, the first section lying inside thesecond section.
 2. An electrical connector according to claim 1, whereinone or more of the biassing means are springs.
 3. An electricalconnector according to claim 1 wherein the first biassing means islocated radially within the second biassing means with respect to thelongitudinal axis of the female component.
 4. An electrical connectoraccording to claim 1 wherein the contact module and the biassing moduleare located within an oil-filled chamber.
 5. An electrical connectoraccording to claim 1 wherein the contact module is accurately seated onthe end of the contact pin.
 6. An electrical connector according toclaim 1, wherein the wiper assembly, in use, provides a seal between thecontact pin and the contact module, whilst assisting with the axialalignment of the components during engagement.
 7. An electricalconnector according to claim 1, wherein the wiper assembly is filledwith electrically insulating grease.
 8. An electrical connectoraccording to claim 1, wherein the female component comprises a femalewiper assembly that remains energised on disconnection of the malecomponent.
 9. An electrical connector according to claim 1, wherein, inuse, at least one contact pin or a sliding element of the contact moduleis connected to a cable by a crimping assembly.
 10. An electricalconnector according to claim 9, wherein the crimping assembly latchesand locks upon insertion of a cable, crimping the contact pin or slidingelement by movement of a sealing boot associated therewith.
 11. Anelectrical connector according to claim 1 wherein a single electricalcontact is formed between the at least one contact pin and the contactmodule.
 12. An electrical connector according to any of the precedingclaims, wherein the female component comprises a housing unit and thecontact module floats radially within the housing unit and iscentralized therein by a biassing means which compensates for radialmisalignment.
 13. An electrical connector according to claim 12, whereinretaining members are located in the housing unit to permanently engagethe contact module such that torsional strain is prevented within thefemale component.